cpl_minixml.cpp

用于读取TAB、MIF、SHP文件的类

/* -------------------------------------------------------------------- */
/*      Anything else is an error.                                      */
/* -------------------------------------------------------------------- */
        else
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Parse error at line %d, unexpected token:%.500s\n", 
                      sContext.nInputLine, sContext.pszToken );
            break;
        }
    }

/* -------------------------------------------------------------------- */
/*      Did we pop all the way out of our stack?                        */
/* -------------------------------------------------------------------- */
    if( CPLGetLastErrorType() == CE_None && sContext.nStackSize != 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Parse error at EOF, not all elements have been closed,\n"
                  "starting with %.500s\n", 
                  sContext.papsStack[sContext.nStackSize-1]->pszValue );
    }

/* -------------------------------------------------------------------- */
/*      Cleanup                                                         */
/* -------------------------------------------------------------------- */
    CPLFree( sContext.pszToken );
    if( sContext.papsStack != NULL )
        CPLFree( sContext.papsStack );

    if( CPLGetLastErrorType() != CE_None )
    {
        CPLDestroyXMLNode( sContext.psFirstNode );
        sContext.psFirstNode = NULL;
    }

    return sContext.psFirstNode;
}

/************************************************************************/
/*                            _GrowBuffer()                             */
/************************************************************************/

static void _GrowBuffer( size_t nNeeded, 
                         char **ppszText, unsigned int *pnMaxLength )

{
    if( nNeeded+1 >= *pnMaxLength )
    {
        *pnMaxLength = MAX(*pnMaxLength * 2,nNeeded+1);
        *ppszText = (char *) CPLRealloc(*ppszText, *pnMaxLength);
    }
}

/************************************************************************/
/*                        CPLSerializeXMLNode()                         */
/************************************************************************/

static void
CPLSerializeXMLNode( CPLXMLNode *psNode, int nIndent, 
                     char **ppszText, unsigned int *pnLength, 
                     unsigned int *pnMaxLength )

{
    if( psNode == NULL )
        return;
    
/* -------------------------------------------------------------------- */
/*      Ensure the buffer is plenty large to hold this additional       */
/*      string.                                                         */
/* -------------------------------------------------------------------- */
    *pnLength += strlen(*ppszText + *pnLength);
    _GrowBuffer( strlen(psNode->pszValue) + *pnLength + 40 + nIndent, 
                 ppszText, pnMaxLength );
    
/* -------------------------------------------------------------------- */
/*      Text is just directly emitted.                                  */
/* -------------------------------------------------------------------- */
    if( psNode->eType == CXT_Text )
    {
        char *pszEscaped = CPLEscapeString( psNode->pszValue, -1, CPLES_XML );

        CPLAssert( psNode->psChild == NULL );

        /* Escaped text might be bigger than expected. */
        _GrowBuffer( strlen(pszEscaped) + *pnLength,
                     ppszText, pnMaxLength );
        strcat( *ppszText + *pnLength, pszEscaped );

        CPLFree( pszEscaped );
    }

/* -------------------------------------------------------------------- */
/*      Attributes require a little formatting.                         */
/* -------------------------------------------------------------------- */
    else if( psNode->eType == CXT_Attribute )
    {
        CPLAssert( psNode->psChild != NULL 
                   && psNode->psChild->eType == CXT_Text );

        sprintf( *ppszText + *pnLength, " %s=\"", psNode->pszValue );
        CPLSerializeXMLNode( psNode->psChild, 0, ppszText, 
                             pnLength, pnMaxLength );
        strcat( *ppszText + *pnLength, "\"" );
    }

/* -------------------------------------------------------------------- */
/*      Handle comment output.                                          */
/* -------------------------------------------------------------------- */
    else if( psNode->eType == CXT_Comment )
    {
        int     i;

        CPLAssert( psNode->psChild == NULL );

        for( i = 0; i < nIndent; i++ )
            (*ppszText)[(*pnLength)++] = ' ';

        sprintf( *ppszText + *pnLength, "<!--%s-->\n", 
                 psNode->pszValue );
    }

/* -------------------------------------------------------------------- */
/*      Handle literal output (like <!DOCTYPE...>)                      */
/* -------------------------------------------------------------------- */
    else if( psNode->eType == CXT_Literal )
    {
        int     i;

        CPLAssert( psNode->psChild == NULL );

        for( i = 0; i < nIndent; i++ )
            (*ppszText)[(*pnLength)++] = ' ';

        strcpy( *ppszText + *pnLength, psNode->pszValue );
        strcat( *ppszText + *pnLength, "\n" );
    }

/* -------------------------------------------------------------------- */
/*      Elements actually have to deal with general children, and       */
/*      various formatting issues.                                      */
/* -------------------------------------------------------------------- */
    else if( psNode->eType == CXT_Element )
    {
        int             bHasNonAttributeChildren = FALSE;
        CPLXMLNode      *psChild;
        
        memset( *ppszText + *pnLength, ' ', nIndent );
        *pnLength += nIndent;
        (*ppszText)[*pnLength] = '\0';

        sprintf( *ppszText + *pnLength, "<%s", psNode->pszValue );

        /* Serialize *all* the attribute children, regardless of order */
        for( psChild = psNode->psChild; 
             psChild != NULL; 
             psChild = psChild->psNext )
        {
            if( psChild->eType == CXT_Attribute )
                CPLSerializeXMLNode( psChild, 0, ppszText, pnLength, 
                                     pnMaxLength );
            else
                bHasNonAttributeChildren = TRUE;
        }
        
        if( !bHasNonAttributeChildren )
        {
            if( psNode->pszValue[0] == '?' )
                strcat( *ppszText + *pnLength, "?>\n" );
            else
                strcat( *ppszText + *pnLength, "/>\n" );
        }
        else
        {
            int         bJustText = TRUE;

            strcat( *ppszText + *pnLength, ">" );

            for( psChild = psNode->psChild; 
                 psChild != NULL; 
                 psChild = psChild->psNext )
            {
                if( psChild->eType == CXT_Attribute )
                    continue;

                if( psChild->eType != CXT_Text && bJustText )
                {
                    bJustText = FALSE;
                    strcat( *ppszText + *pnLength, "\n" );
                }

                CPLSerializeXMLNode( psChild, nIndent + 2, ppszText, pnLength, 
                                     pnMaxLength );
            }
        
            *pnLength += strlen(*ppszText + *pnLength);
            _GrowBuffer( strlen(psNode->pszValue) + *pnLength + 40 + nIndent, 
                         ppszText, pnMaxLength );

            if( !bJustText )
            {
                memset( *ppszText + *pnLength, ' ', nIndent );
                *pnLength += nIndent;
                (*ppszText)[*pnLength] = '\0';
            }

            *pnLength += strlen(*ppszText + *pnLength);
            sprintf( *ppszText + *pnLength, "</%s>\n", psNode->pszValue );
        }
    }
}
                                
/************************************************************************/
/*                        CPLSerializeXMLTree()                         */
/************************************************************************/

/**
 * \brief Convert tree into string document.
 *
 * This function converts a CPLXMLNode tree representation of a document
 * into a flat string representation.  White space indentation is used
 * visually preserve the tree structure of the document.  The returned 
 * document becomes owned by the caller and should be freed with CPLFree()
 * when no longer needed.
 *
 * @param psNode
 *
 * @return the document on success or NULL on failure. 
 */

char *CPLSerializeXMLTree( CPLXMLNode *psNode )

{
    unsigned int nMaxLength = 100, nLength = 0;
    char *pszText = NULL;
    CPLXMLNode *psThis;

    pszText = (char *) CPLMalloc(nMaxLength);
    pszText[0] = '\0';

    for( psThis = psNode; psThis != NULL; psThis = psThis->psNext )
        CPLSerializeXMLNode( psThis, 0, &pszText, &nLength, &nMaxLength );

    return pszText;
}

/************************************************************************/
/*                          CPLCreateXMLNode()                          */
/************************************************************************/

/**
 * \brief Create an document tree item.
 *
 * Create a single CPLXMLNode object with the desired value and type, and
 * attach it as a child of the indicated parent.  
 *
 * @param poParent the parent to which this node should be attached as a 
 * child.  May be NULL to keep as free standing. 
 *
 * @return the newly created node, now owned by the caller (or parent node).
 */

CPLXMLNode *CPLCreateXMLNode( CPLXMLNode *poParent, CPLXMLNodeType eType, 
                              const char *pszText )

{
    CPLXMLNode  *psNode;

/* -------------------------------------------------------------------- */
/*      Create new node.                                                */
/* -------------------------------------------------------------------- */
    psNode = (CPLXMLNode *) CPLCalloc(sizeof(CPLXMLNode),1);
    
    psNode->eType = eType;
    psNode->pszValue = CPLStrdup( pszText );

/* -------------------------------------------------------------------- */
/*      Attach to parent, if provided.                                  */
/* -------------------------------------------------------------------- */
    if( poParent != NULL )
    {
        if( poParent->psChild == NULL )
            poParent->psChild = psNode;
        else
        {
            CPLXMLNode  *psLink = poParent->psChild;

            while( psLink->psNext != NULL )
                psLink = psLink->psNext;

            psLink->psNext = psNode;
        }
    }
    
    return psNode;
}

/************************************************************************/
/*                         CPLDestroyXMLNode()                          */
/************************************************************************/

/**
 * \brief Destroy a tree. 
 *
 * This function frees resources associated with a CPLXMLNode and all its
 * children nodes.  
 *
 * @param psNode the tree to free.
 */

void CPLDestroyXMLNode( CPLXMLNode *psNode )

{
    if( psNode == NULL )
        return;

    if( psNode->psChild != NULL )
        CPLDestroyXMLNode( psNode->psChild );
    
    if( psNode->psNext != NULL )
        CPLDestroyXMLNode( psNode->psNext );

    CPLFree( psNode->pszValue );
    CPLFree( psNode );
}

/************************************************************************/
/*                           CPLSearchXMLNode()                         */
/************************************************************************/

/**
 * \brief Search for a node in document.
 *
 * Searches the children (and potentially siblings) of the documented
 * passed in for the named element or attribute.  To search following
 * siblings as well as children, prefix the pszElement name with an equal
 * sign.  This function does an in-order traversal of the document tree.
 * So it will first match against the current node, then it's first child,
 * that childs first child, and so on. 
 *
 * Use CPLGetXMLNode() to find a specific child, or along a specific
 * node path. 
 *
 * @param psRoot the subtree to search.  This should be a node of type
 * CXT_Element.  NULL is safe. 
 *
 * @param pszElement the name of the element or attribute to search for.
 *
 * @return The matching node or NULL on failure. 
 */

CPLXMLNode *CPLSearchXMLNode( CPLXMLNode *psRoot, const char *pszElement )

{
    int         bSideSearch = FALSE;
    CPLXMLNode *psChild, *psResult;

    if( psRoot == NULL || pszElement == NULL )
        return NULL;

    if( *pszElement == '=' )
    {
        bSideSearch = TRUE;
        pszElement++;
    }

/* -------------------------------------------------------------------- */
/*      Does this node match?                                           */
/* -------------------------------------------------------------------- */
    if( (psRoot->eType == CXT_Element 
         || psRoot->eType == CXT_Attribute)
        && EQUAL(pszElement,psRoot->pszValue) )
        return psRoot;

/* -------------------------------------------------------------------- */